1. Technical Field
The present invention relates to a tool unclamping system for a machine tool, and more particularly to a servo-driven tool unclamping system for the machine tool which numerically controls a tool change arm to operate and controls a spindle to clamp and unclamp tools in different operating tracks.
2. Description of Related Art
A conventional machine tool contains an ATC system with a cam box, the cam box has two roller gear cams for driving a driven roller set to actuate a rotation of a tool change arm, and the two roller gear cams drive a connecting rod assembly to move the tool change arm upwardly and downwardly, wherein when the tool change arm rotates below a spindle, a tool on the spindle is unclamped or clamped after a sensor detects a position of the tool change arm. After confirming the tool change arm is positioned, the sensor transmits a signal to start a hydraulic cylinder or a pneumatic cylinder on the spindle so that a drive post of a tool unlock mechanism is driven by the hydraulic cylinder or the pneumatic cylinder to actuate the spindle, such that the spindle unclamps the tool and the tool change arm changes the tool.
However, a tool unclamping and clamping of the spindle and a vertical movement of the tool change arm cannot be realized simultaneously, because when the sensor confirms the signal, the tool changing operation pauses several times to prolong tool change time and working time. In addition, the tool change arm and the tool unlock mechanism of the spindle are driven by a mechanical structure or a hydraulic structure, so before changing the tool, a worker has to adjust the machine tool manually, thus causing operational inconvenience. Also, a connecting structure between the tool change arm and the tool unlock mechanism of the spindle is complicated and has a large size, thus occupying configuration space and increasing maintenance difficult.
Furthermore, when a cylinder of the tool unlock mechanism is in a tool unclamp stroke, a distance between the drive post and a pull stud is adjusted by using a washer, thereby complicating the tool unlock mechanism.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.